
TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS
SYSTEM DESCRIPTION Idle
AirControl Valve(IACV) -Auxiliary Air
Control (AAC)Valve
Camshaft positionsensor Engine
speed
I
Mass
airflow sensor Amount
ofintake air
I
Engine coolant temperature sensor Engine
coolant temperature
~
I
Ignition switch Start
signal
I
Throttle positionsensor Throttle
position
~
I
Inhibitor switch(A/Tmodels)/
Park/Neutralposition
Neutral position switch(M/Tmodels) ECM
(ECCS
Air conditioner operation control
!
IACV-AAC valve
I
Air conditioner switch
module)
Power steering oilpressure switch Power
steering loadsignal
I
Battery
~
Battery voltage
Vehicle speedsensor Vehicle
speed
Cooling fanrelay Cooling
fanoperation
Load switch' Electrical
load
Blower fanswitch Blower
fanoperation
': Rear window defogger switchandheadlamp switch.
This system automatically controlsengineidlespeed toaspecified level.Idlespeed iscontrolled
through fineadjustment ofthe amount ofair which bypasses thethrottle valveviaIACV-AAC valve.The
IACV-AAC valveopens andcloses (except forEurope andIsrael), orrepeats ON/OFF operation (for
Europe andIsrael), according tothe signal sentfrom theECM. Thecamshaft positionsensordetects
the actual engine speedandsends asignal tothe ECM. TheECM thencontrols theIACV-AAC valveso
that engine speedcoincides withthetarget valuememorized inECM. Thetarget engine speedisthe
lowest speedatwhich theengine canoperate steadily. Theoptimum valuestored inthe ECM isdeter-
mined bytaking intoconsideration variousengineconditions, suchasduring warmup,deceleration, and
engine load(airconditioner, powersteering andcooling fanoperation).
COMPONENT DESCRIPTION
IACV-AAC valve-Except forEurope andIsrael
The IACV-AAC valveismoved byopen andclose signals from
the ECM. When theopen signal issent tothe valve, theamount
of air that willflow through thevalve increases. Themore air
that flows through thevalve, thehigher theidle speed. When
the close signal issent tothe valve. theamount ofair
decreases.
EC-150

Repairharness orcon-
nectors. INSPECTION
END
Check thefollowing.
• Harness connectors
QD,@orQD,
@
• 10A fuse
• Harness foropen or
short between IACV-AAC
valve andfuse
If NG, repair harness or
connectors.
NG OK
NG
OK
INSPECTION
START
CHECK OVERALL FUNCTION.
1. Start engine andwarm itup suffi-
ciently.
2. Check idlespeed.
If NG, adjust idlespeed.
~ 3.• Perform "AACVALVE
~ ADJ"or"IACV-AACIV
ADJ" in"WORK
SUPPORT" modewith
CONSULT.
• Disconnect throttleposi-
tion sensor harness con-
nector.
4. Make surethatidlespeed drops.
OK
@
CHECK
POWER SUPPLY.
1. Stop engine.
2. Disconnect IACV-AACvalveharness
connector.
3. Turn ignition switch"ON".
4. Check voltage between terminal
@
or
G)
and ground.
Voltage: Batteryvoltage
CHECK OUTPUT SIGNALCIRCUIT.
1. Turn ignition switch"OFF".
(ij\
2.Reconnect IACV-AACvalve
~ harnessconnector andthen
start engine.
3. Perform "IACV-AACIV
SYSTEM" in"FUNCTION
TEST" modewithCONSULT.
OR
(F.I\
3.Perform "IACV-AACIV
~ OPENING" in"ACTIVE TEST"
mode withCONSULT.
OR
M
2.Disconnect ECMharness con-
~ nectar.
3. Check harness continuity
between ECMterminal
(ill)
or
@
and terminal
@,
ECM
terminal
GID
or
@
and
terminal
@.
Continuity shouldexist.
If
OK, check harness forshort.
SEF233R
SEF142NC
o
•
ACTIVE TEST.
LET
ENGINE IDLE
THEN
TOUCH START
(AiC
SW-UGHT SWOFF)
•
IACV-AACN SYSTEM.
I ACV-AACN 34%
OPENING
==========
MONITOR
==========
CMPS-RPM (REF)712rpm
MAS AIRIFL SE 1.13V
COOLAN TEMPtS 92°C
TROUBLE
DIAGNOSIS FORNON-DETECTABLE ITEMS
ffiJ
Idle AirControl Valve(IACV) -Auxiliary Air
Control (AAC)Valve(Cont'd)
DIAGNOSTIC PROCEDURE
!:::=====mul===
I
NEXT" START
I
MEF176E
CD
:
For Europe andIsrael
@ :
Except forEurope andIsrael
~
Ii)
~i5~i5
dfu
CillffuID
illU--illU
~[]fl[OOWN][Qill SEF484Q
EC-154

TROUBLEDIAGNOSIS FORNON-DETECTABLE ITEMS
SYSTEM DESCRIPTION Idle
AirControl Valve(IACV) -Auxiliary Air
Control (AAC)Valve
Camshaft positionsensor Engine
speed
~
I
Amount ofintake air
Mass airflow sensor
I
Engine coolant temperature sensor Engine
coolant temperature
I
Ignition switch Start
signal
I
Throttle position sensor Throttle
"position
I
ECM
Inhibitor switch(A/Tmodels)/ Park/Neutral
position (ECCS
control
!
IACV-AAC valve
I
Neutral position switch(M/Tmodels)
module)
Air conditioner switch Air
conditioner operation
Power steering oilpressure switch Power
steering loadsignal
I
Battery Battery
voltage
Vehicle speedsensor Vehicle
speed
I
l
Cooling fan Cooling
fanoperation
I
This system automatically controlsengineidlespeed toaspecified level.Idlespeed iscontrolled
through fineadjustment ofthe amount ofair which bypasses thethrottle valveviaIACV-AAC valve.The
IACV-AAC valverepeats ON/OFF operation according tothe signal sentfrom theECM. Thecamshaft
position sensordetects theactual engine speedandsends asignal tothe ECM. TheECM thencontrols
the ON/OFF timeofthe IACV-AAC valvesothat engine speedcoincides withthetarget valuememo-
rized inECM. Thetarget engine speedisthe lowest speedatwhich theengine canoperate steadily.
The optimum valuestored inthe ECM isdetermined bytaking intoconsideration variousengine
conditions, suchasduring warmup,deceleration, andengine load(airconditioner, powersteering and
cooling fanoperation).
COMPONENTDESCRIPTION
IACV-AAC valve
The IACV-AAC valveismoved byON/OFF pulsesfromtheECM.
The longer theONpulse, thegreater theamount ofair that will
flow through thevalve. Themore airthat flows through the
valve, thehigher theidle speed.
Air SEF040E
EC-335
•

•IGN TIMING ADJ.
0
TROUBLE
DIAGNOSIS FORNON-DETECTABLE ITEMS
[ill
Idle AirControl Valve(IACV) -Auxiliary Air
Control (AAC)Valve(Cont'd)
DIAGNOSTIC PROCEDURE
-- CONDITION SETIING--
IGN/T FEEDBACK HOLD INSPECTION
START
~i5 ~i5
ECM
E[CONNECTORII
cffb
113
=
= =
MONITOR
CAS. RPM (REF)
IGN TIMING
IDLE POSITION
---
---
800rpm
15BTDC
ON
SEF786KA
MEC768B CHECK
OVERALL FUNCTION.
1. Start engine andwarm itup suffi-
ciently.
2. Check idlespeed.
800::1:50
rpm
If NG, adjust idlespeed. (Referto
(l)
e
EC-243.)
3. .. •Perform "IGNTIMING ADJ"
I!I
in"WORK SUPPORT" mode
with CONSULT.
~ •Disconnect IACV-AACvalve
5
harness connector.
4. Ma esure thatidlespeed drops.
Does notdrop
CHECK POWER SUPPLY.
1. Stop engine.
2. Disconnect IACV-AACvalveharness
connector.
3. Turn ignition switch"ON".
4. Check voltage between terminal
G)
and ground withCONSULT ortester.
Voltage: Batteryvoltage
OK
[!1
CHECK OUTPUT SIGNALCIRCUIT.
1. Disconnect ECMharness connector.
2. Check harness continuity between
ECM terminal
CTID
andterminal
(2).
Continuity shouldexist.
If OK, check harness forshort
OK
CHECK COMPONENT
(IACV-AAC valve).
Refer to"COMPONENT INSPECTION"
on next page.
OK Drops
NG
NG
NG INSPECTION
END
Check thefollowing .
• Harness connectors
@D,
([ill)(M/Tmod-
els)
• Harness connectors
@,
@
(A/T
models)
• 7.5A fuse
• Harness foropen or
short between IACV-
AAC valve harness con-
nector andfuse
If NG, repair harness or
con nectors.
Check thefollowing.
• Harness connectors
@,@D
• Harness foropen or
short between ECMand
IACV-AAC valve
If
NG, repair harness or
connectors.
Replace IACV-AAC valve.
•
Disconnect andreconnect harnesscon-
nectors inthe circuit Thenretest
Trouble isnot fixed.
Check ECMpinterminals fordamage
and check theconnection ofECM har-
ness connector. ReconnectECMhar-
ness connector andretest
INSPECTION END
EC-337

SUPPLEMENTALRESTRAINTSYSTEM(SRS)
Description
The airbag deploys ifthe diagnosis sensorunitactivates whiletheignition switchisinthe "ON" or
"START" position.
Single anddual airbag systems
Ignition
switch
(ON orSTART)
Driver
air
bag module
Diagnosis sensorunit
• Auxiliary powersource (condenser)
• CPU
Battery
Seat beltpre-tensioner
G-Iorce whendecelerating
(greater thanthepredetermined setting)
o
Drive circuit
• G sensor
• Saling sensor Passenger
airbag module
(For dual airbag system)
MRS069AB
Mechanical sensor
Seat belt Mechanical
trigger
Retractor shaft Piston
andwire rope
•
Combined intoseat beltretractor
SRS126
RS-9